I wasn't able to open that web page of the circular, but does it say anything about leverage ?
The exchanges may neutralize this move by increasing the leverage, as in the CDS segment
The one thing the government can't afford is reduction in the volumes. Nowadays the average volume tends to be about 3 lakh crores per day. That is a serious revenue stream for the government. Increasing the leverage will be the workaround needed to keep that figure and take it further up.
e.g. the lot size for NF may increase to 60, but NSE may ask for only 5% for the contract instead of the present 10%.